My personal experience, Galaxy watch 5 pro is really good with Outdoor running but pratically useless with Treadmill running accuracy (this observations made vs Garmin Venu 2 plus)
In General Galaxy watch 5 pro is 20% behind with Treadmill distance/Running, however if you turn off GPS, I noted the accuracy gets much improved to or rather closer to 10%
Try it out if you are into....... Running
